Relativistic Calculations for Photonuclear Reactions (III): A Consistent Relativistic Analysis of the (e,e'p) and (gamma,p) Reactions

Relativistic calculations for the quasifree electron scattering process (e, e'p) and the direct knockout contribution to (gamma, p) reactions are presented. The spectroscopic factors determined from the former reaction are used to fix the magnitude of the knockout contribution to the (gamma, p) reaction at 60 MeV. The results obtained for several nuclei indicate that the knockout contributions are much larger in magnitude and hence closer to the data than predicted in an earlier comparison based on non-relativistic calculations. We discuss the sensitivity of the results to the choice of parameters for the binding and final state interactions. We find these uncertainties to be more pronounced at the larger missing momenta explored by the (gamma, p) reaction. The implications of the present results for the size of contributions due to meson exchange currents are discussed.Comment: LaTeX, 21 pages including 5 figures, submitted to Nuc. Phys.

A molecular dynamics boundary condition for heat exchange between walls and a fluid

In molecular dynamics simulations of heat transfer in micro channels, a lot of computation time is used when the wall molecules are explicitly simulated. To save computation time, implicit boundary conditions, such as the Maxwell conditions, can be used. With these boundary conditions, heat transfer is still a problem. In this work, we derive a new boundary condition based on a vibrating potential wall. The heat-transfer properties of the new boundary condition are shown to be comparable with those of the explicit wall. The computation time needed for the implicit boundary condition is very small compared with that needed for the explicit simulation

Evidence for Partial Occupancy of the 3s_1/2 Proton Orbital in 208-Pb

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

A consistent analysis of (e,e'p) and (d,3He) experiments

The apparent discrepancy between spectroscopic factors obtained in (e,e'p) and (d,3He) experiments is investigated. This is performed first for 48Ca(e,e'p) and 48Ca(d,3He) experiments and then for other nuclei. It is shown that the discrepancy disappears if the (d,3He) experiments are re-analyzed with a non-local finite range DWBA analysis with a bound-state wave function that is obtained from (e,e'p) experiments.Comment: 23 pages, 7 figure

Patients’ perceptions of 70-gene signature testing: commonly changing the initial inclination to undergo or forego chemotherapy and reducing decisional conflict

PURPOSE: Little is known about the impact of 70-gene signature (70-GS) use on patients' chemotherapy decision-making. The primary aim of this study was to evaluate the impact of 70-GS use on patients' decisions to undergo chemotherapy. The perceived decision conflict during decision-making was a secondary objective of the study. METHODS: Patients operated for estrogen receptor positive early breast cancer were asked to fill out a questionnaire probing their inclination to undergo chemotherapy before deployment of the 70-GS test. After disclosure of the 70-GS result patients were asked about their decision regarding chemotherapy. Patients' decisional conflict was measured using the 16-item decisional conflict scale (DCS); scores  37.5 implies that one feels unsure about a choice. RESULTS: Between January 1th 2017 and December 31th 2018, 106 patients completed both questionnaires. Before deployment of the 70-GS, 58% of patients (n = 62) formulated a clear treatment preference, of whom 21 patients (34%) changed their opinion on treatment with chemotherapy following the 70-GS. The final decision regarding chemotherapy was in line with the 70-GS result in 90% of patients. The percentage of patients who felt unsure about their preference to be treated with chemotherapy decreased from 42 to 5% after disclosure of the 70-GS. The mean total DCS significantly decreased from pre-test to post-test from 35 to 23, irrespective of the risk estimate (p < 0.001). CONCLUSION: Deployment of the 70-GS changed patients' inclination to undergo adjuvant chemotherapy in one third of patients and decreased patients' decisional conflict

The 3^3He(e, e′'d)p Reaction in qω\omega-constant Kinematics

The cross section for the $^3$He(e, e$'$d)p reaction has been measured as a function of the missing momentum $p_m$ in q$\omega$ -constant kinematics at beam energies of 370 and 576 MeV for values of the three-momentum transfer $q$ of 412, 504 and 604 \mevc. The L(+TT), T and LT structure functions have been separated for $q$ = 412 and 504 \mevc. The data are compared to three-body Faddeev calculations, including meson-exchange currents (MEC), and to calculations based on a covariant diagrammatic expansion. The influence of final-state interactions and meson-exchange currents is discussed. The $p_m$-dependence of the data is reasonably well described by all calculations. However, the most advanced Faddeev calculations, which employ the AV18 nucleon-nucleon interaction and include MEC, overestimate the measured cross sections, especially the longitudinal part, and at the larger values of $q$. The diagrammatic approach gives a fair description of the cross section, but under(over)estimates the longitudinal (transverse) structure function.Comment: 17 pages, 7 figure

Overlap functions in correlation methods and quasifree nucleon knockout from 16^{16}O

The cross sections of the ($e,e'N$) and ($\gamma,p$) reactions on $^{16}$O are calculated, for the transitions to the $1/2^{-}$ ground state and the first $3/2^{-}$ excited state of the residual nucleus, using single-particle overlap functions obtained on the basis of one-body density matrices within different correlation methods. The electron-induced one-nucleon knockout reaction is treated within a nonrelativistic DWIA framework. The theoretical treatment of the ($\gamma,p$) reaction includes both contributions of the direct knockout mechanism and of meson-exchange currents. The results are sensitive to details of the different overlap functions. The consistent analysis of the reaction cross sections and the comparison with the experimental data make it possible to study the nucleon--nucleon correlation effects.Comment: 26 pages, LaTeX, 5 Postscript figures, submitted to PR

Electron-induced neutron knockout from 4^{4}He

The differential cross section for electron-induced neutron knockout in the reaction 4He(e,e′n)3He has been measured for the first time with a statistical accuracy of 11%. The experiment was performed in quasielastic kinematics at a momentum transfer of 300  MeV/c and in the missing-momentum range of 25–70  MeV/c. The comparison of the data with theoretical calculations shows an impressive increase of the cross section resulting from final state interaction effects. Specifically , the p−n charge-exchange process dominates the cross section in this kinematical regime. (APS